This invention relates to electromagnetic discharge apparatus. More particularly, it is concerned with electrodeless fluorescent light sources.
Electrodeless light sources which operate by coupling high frequency power to an arc discharge in an electrodeless lamp have been developed. These light sources typically include a high frequency power source connected to a coupling fixture having an inner conductor and an outer conductor disposed around the inner conductor. The electrodeless lamp is positioned adjacent to the end of the inner conductor. High frequency power is coupled to a light emitting electromagnetic discharge within the electrodeless lamp. A portion of the coupling fixture passes radiation at the frequencies of light produced, this permitting the use of the apparatus as a light source.
Electrodeless fluorescent light sources are known in which the electrodeless lamp emits ultraviolet radiation which impinges on phosphors which in turn emit visible light when the ultraviolet radiation is absorbed. Examples of fluorescent light sources of this general type are disclosed in U.S. Pat. Nos. 4,119,889 to Donald D. Rollister, 4,005,330 to Homer H. Glascock, Jr. and John M. Anderson, 4,189,661 to Paul O. Haugsjaa and Edward F. White, and 4,266,167 to Joseph M. Proud and Donald H. Baird.